Constant velocity joint



May 11, 1943. E. B. ANDERSON CONSTANT VELOCITY JOINT Filed Sept. 21, 1940 Patented May 11, 1943 CONSTANT VELOCITY JOINT I Edmund B. Anderson, Rockford, Ill., assignor to Borg-Warner Corporation, Chicago, lll., a corporation of Illinois Application September 21, 1940, Serial No. 357,739

3 Claims.

This invention relates to constant velocity universal joints of the type wherein torque is transmitted from one of the joint-elements to the other through the medium of balls operating in raceways formed in the respective elements. The invention relates particularly to-joints of this type wherein the raceways extend diagonally in a generally axial direction, with the raceways of 2 each pair in crossed relationship to each other and with a torque-transmitting ball located at the crossing of each pair of raceways.

In a universal joint of this type. the torque reaction of the crossed raceways develops thrust against the balls in an axial direction. In my prior Patent No. 2,047,660,- issued July 14, 1936, I have disclosed a joint of this type which is provided with a pair of thrust-reaction rings arranged in axial thrust-bearing engagement with the outer or female torque-transmitting element and embracing the balls between them so as to take the axial thrust of the balls and maintain the ball in properly centered relationship. In

the joint shown in that patent, the thrust-upon all, of the balls is in the same direction, the direction depending upon the direction in which torque is transmitted from one element to the other.

The present invention has as its primary object to improve upon the' construction shown in said prior patent, by arranging for the axial thrust upon the balls to be equally distributed in both directions.

' Other objects, the advantages and uses of the invention will become more apparent after reading the following specification and claims, and after consideration of the drawings forming a part of the specification, wherein:

Fig. 1 is an axial sectional view of a universal joint embodying the invention;

Fig. 2 is an exploded axial sectional view of parts of the joint;

Fig. .3 is a partial sectional view of a modified form of the invention; and

Fig. 4 is a partial sectional view of another modified form of the invention.

As an example of one form in which my invention may be embodied, I have shown in the drawing a constant velocity universal joint comprise ing male and female torque-transmitting elements l and ll respectively, each adapted to be attached to one of a pair of shaft sections to be drivingly connected by the joint. One of said shaft sections is shown. at I2, having a splined end portion l3 on which the male element i0 is se cured. The otlw' shaft section is shown at it asbeing formed integrally with the female element The male element. I has an outer surface It formed as a zone of a sphere and the female element H has an inner surface l6 formed as a zone of a sphere on a radius sufliciently larger than the radius of the surface l5 to accommodate between the two surfaces the thrust reaction rings which will be described more fully hereinafter.

Formed in the male element H) are a pinrality of external arcuate raceways l8 and i9 respectively. Formed in the female element H are a plurality of internal arcuate raceways 20 and 2| respectively. Each of the raceways l8, 80, 2

and 28 are disposed along great circles, i. e., on arcs struck from the centers of their respective elements from which centers the zonal surfaces l5 and I6 are likewise generated. In cross-section the raceways are preferably semi-circular.

The raceways l8 and 20 are associated together in pairs and the raceways l9 and 2| are likewise associated together in alternate pairs. Between 7 the respective pairs of raceways are disposed balls 22 and 220 which are received in their respective raceways so as to transmit torque between the elements i0 and II.

Each of the raceways is inclined with reference to' a meridian or great circle passing through the axis of its respective element, the

, the balls. Such axialthrust is taken by a pair of zone-shaped thrust rings 23 and 24 which are shaped so as to fit rather snugly within the zonal surfaces l5 and It with just enough clearance to permit iree sliding movement between the surfaces of the thrust rings and the surfaces l5 and l6 during operation of the joint.

Thrust exerted against the thrust rings 23 and 24 will be transmitted from the rings to the surface: iii of the female element H.

The engagement between the rings 23, 24 and the surface l5 serves, in conjunction with the engagement between the thrust rings and the ,ments l and II.

surface I6, to hold the elements and "I l in asballs 22a will be urged axially in the other direction. For example, assuming the member II to be the driving member and to be rotating in the direction indicated by the arrow 25, the balls 22 will be urged in the direction indicated by the arrow 26 and the balls 22a will be urged in the direction indicated by the arrow 26a. Thus, in

- the particular form of the invention shown wherein six pairs of raceways and balls are employed, three of the balls will be urged axially in one direction and the other three will be urged axially in the other direction. Each series of three balls being equally distributed around the circumference of the joint, there will be a uniform axial pressure against each of the thrust rings 23, 24, tending to urge them apart. This results in a balancing of the axial forces reacting on the several parts of the joint and maintains the parts in accurately centered relationship at all times.

The arrangement of the raceways with alternate inclination provides the further advantage of utilizing the balls 22, 22a. not only as torquetransmitting connections but also as means for resisting axially separating movement of the eleerate with the thrust rings 23 and 24 in maintaining the elements in centered relationship axially.

The rings 23, 24 may if desired, be provided with lug portions 21 extending between the balls 22, 23a and increasing the bearing surface of the ring against the surface l5, 16 respectively.

The mouth of the female element II is slightly larger than the maximum diameter of the male element It so as to permit the latter to be freely inserted therethrough. This may be accomplished in either of several difierent ways. The corner of the ridges defined between the raceways 20, 2| may be removed as indicated at 29 in Fig. 1. The difference between the diameters of the surfaces I5 and I6 may be made sufficiently large so that the diameter of the surface is less than the diameter of the mouth of the female element. In thus increasing the'spacing between the surfaces 15 and IS the thickness of the thrust rings 23 and 24 would be correspondingly increased. This modification of the invention is shown in Fig. 3. A third arrangement whereby the maximum diameter of the male element may be made smaller than the mouth of the female element, is to form the intermediate region of the male element In with a cylindrical surface 35, thus reducing the diameter of such intermediate region without reducing the radius of the zonal surfaces 15a formed on either side of such intermediate surface 35. This form of the invention has the advantage that it does not materially decrease the effective thrust bearing surface of the male element i5, since most of the effective bearing surface many -to that of the raceway i9. As a result, the balls 22 will be urged axially in one direction and the In this respect the balls coopform of the invention is confined to the side regions where the inclination'of the bearing surface with reference to the axis of rotation of the joint is at a maximum. This modification of the invention is shown in Fig. 4. Such reduction of female element. For example, it is contemplated that the thrust rings 23 and 24 may be passed through the mouth of the female element by accommodating diametrically opposed regions of the rings 23 and 24 each in a pair of chordally opposed raceways 2D or 21. Using this method of assembly, the two thrust rings will be first assembled against the respective sides of the male element 10, the assembly positioned with its axis at right angles to the axis of the female element 'l I, with one of the thrust rings positioned in a plane passing through the outer extremities of two of the raceways 2B, and with the other thrust ring positioned in a parallel plane passing through the outer extremities of two of the raceways 2i. The assembly may then be passed through the mouth of the female element and rotated into a position wherein its axis is aligned with the axis of the female element. In order to permit this to be accomplished, the lugs 21 of the rings 23 and 24 may be terminated considerably short of the median or equatorial plane of surfaces l5, 16, as shown in Fig. 4. The restriction of the area of the lugs 21 does not reduce the effective thrust bearing surface as long as the total width of the thrust rings is not thereby made less than that of the zonal surfaces l5a.

After having assembled the thrust rings and male element with the female element, the balls are inserted byany suitable known method, such as for example as by oscillating the thrust ring and male element assembly to successive positions wherein the openings defined between pairs of registering notches between the projections 21, are exposed outside of the mouth of the female element l I so as to permit the balls to be dropped through such openings and into the raceways I8 and IS.

The shaft 12 is then inserted in the bore of the male element [0 and the shaft and male element are cooked to a position wherein the axis of the shaft I2 i aligned with an opening 33 in the female element ll. Through the opening 33 a screw 30 is inserted through a washer 3| that has been previously seated against a shoulder 32 in one end of the bore of the male element l0, and is threaded by means of a tool inserted through said opening into the end of the shaft I2 until the shaft has been tightly secured in the element In. In this respect, the invention provides an improved method of attaching the male element of a constant velocity universal joint to its shaft. While two of the openings 33 have been shown, only one is necessary for the assembling operation above described, the other-opening being for balancing purposes.

I claim:

1. In a constant velocity universal joint, male and female torque transmitting elements coopereach disposed on a great circle of its respective element and extending diagonally with reference to a meridian thereof, the raceways of each pair having opposite meridional inclination and being in crossed relation to each other, a ball disposed at the crossing of each pair of raceways and received in-the respective raceways for forming a torque-transmitting connection between the elements, and a pair of opposed annular thrust receiving elements embracing said balls between them and disposed between the opposed surfaces of the elements and in thrust bearing engagement therewith, the meridional inclination of the raceways of alternate pairs being opposite to that of the raceways of the intervening pairs, whereby the axial thrust against the balls resulting from the torque reaction of the crossed grooves against the balls is directed alternately in opposite directions resulting in the constant maintenance of the external faces of both of said rings in snug engagement with the internal face of the female element.

2. A constant velocity universal joint comprising male and female torque-transmitting elements having opposed external and internal zone-shaped surfaces respectively, and cooper atively providing circumferentially spaced pairs of arcuate ball raceways, each disposed along a great circle of and inclined with reference to a meridian of its respective element, the meridional inclination of one raceway of a respective pair being opposite that of the other raceway whereby the raceways of each pair are disposed in crossthe element, said rings embracing the balls between them and arranged to take the axial thrust developed in the balls by the torque reaction of the crossed raceways thereagainst, the meridional inclination of the raceways of alternate pairs being opposite to that of the 'raceways of the intervening pairs, whereby said torque-reactional thrust is applied to the balls alternately in opposite directions so as to cause alternate balls to bear against one of said rings and the intervening balls to bearagainst the other of said rings resulting in the constantmaintenance of the,extemal faces of both of said rings in snug engagement with the internal face of the female element. .j

3. A universal joint comprising a cup-shaped female element and a zone-shaped male element received therein, said elements having internal and external ball raceways respectively, spherical torque-transmitting elements disposed in said raceways, a shaft extending into said male element, and a securing element threadedinto the inner end of said shaft, for securing the same in said male element, said female element having a hub region and, at one side of the hub region an opening extending diagonally towards the center of the joint, through which said securing relationship, a ball located at the crossing oi each pair and received in the respective raceways element is adapted to be inserted into the end of said shaft in one position of the latter.

EDMUND B. ANDERSON. 

